The present invention relates to a method and apparatus for recovering and reusing the solvent in a dry cleaning system.
In conventional dry cleaning systems, the effulent vapors or fumes of the solvent such as perchlorethylene (PERC) emanating from the dry cleaning washing machine and dryers generally are vented directly to the atmosphere and thus pollute the atmosphere. By being so vented, they are also lost for reuse. Thus, the escaping vapors not only produce an environmental hazard, but their loss are extremely costly to the dry cleaning establishment.
Attempt has been made to remove the solvent vapor contained in the air-stream from a dry cleaning machine by passing the solvent laden air-stream through a bed of activated carbon. The carbon adsorbs the solvent vapor or gas held in the air-stream, allowing the thus cleaned air to pass through the carbon bed to atmosphere. See Fuhring et al U.S. Pat. Nos. 3,203,110 and 3,538,615. Unfortunately, the carbon bed will only adsorb approximately one gallon of solvent per 80 lb of carbon before becoming saturated with solvent vapor, and must then be de-adsorbed by passing a "blanket" of steam through the carbon bed in a reverse direction to that of adsorption. The steam and solvent vapors form an azeotrope which must then be condensed, and the resultant water and liquid solvent must be separated according to their specific gravities. Thereafter, the solvent may then be recycled for reuse.
In the foregoing case, expensive and complex equipment is required to provide the carbon, the "steam" cleaning or the cooling condensers, as well as the extensive control equipment necessary for their function. In conventional commercial dry cleaning establishments, the cost for such equipment and for the skilled personnel necessary to operate the equipment is prohibitive.
It is the object of the present invention to economically, simply and with a minimum of equipment and the elimination of attendant personnel, to recapture the cleaning solvent and to reuse the same so that as a result thereof, the solvent is not vented to the atmosphere and thus pollution of the atmosphere is avoided.
It is a further object of the present invention to combine the normally separate dry cleaning washer, and dry cleaning dryer into a closed circulatory system, wherein the heat and cooling necessary to vaporize and condense the solvent are produced in situ without the need for external auxiliary equipment.
It is yet another object of the present invention to provide a closed system for the recovery and reuse of the solvent so that virtually no solvent is vented or lost to atmosphere thereby reducing the threat of any pollution, and the maximization of solvent use.
These objects as well as others will be apparent from the following disclosure.